Delayed hypersensitivity. We will attempt to obtain more consistent and reproducible production of migration inhibitory factor by incubating sensitized lymph node and uveal tract cells with a higher concentration of bovine gamma globulin (BGG). Culture supernatant fluids will be tested for their ability to inhibit the migration of normal guinea pig peritoneal cells. Nonspecific alteration of ocular immune response. The effect of Concanavalin A on the secondary response to BGG will be investigated. Rabbits that have been immunized intravitreally with BGG will be treated with Concanavalin A prior to a second intravitreal injection of BGG into the previously uninjected eye. The anti-BGG plaque forming cell response in the uveal tracts and draining lymph nodes will be determined. We will continue our studies of the effect of Cytoxan on the response to BGG. Various Cytoxan concentrations and treatment schedules will be used to determine the lowest amount of the drug that will inhibit uveal tract antibody production and ocular inflammation. Ocular immune competent cells. We will use the rosette test to detect antigen binding cells and the plaque assay to detect antibody producing cells in the uveal tracts of rabbits at various times after intravitreal injection of BGG. BIBLIOGRAPHIC REFERENCES: Hall, J. M. Meyer, R.F., Smolin, G., and Okumoto, M.: Effect of pretreatment with local cortiscosteroids on antibody-forming cells in the eye and draining lymph nodes. Canad. J. Ophthal. 10:487-493 1975. Hall, J. M., Pribnow, J.F., Besemer, D.J., and Vedros, N.A.: Nonspecific resistance to introaocular infection: nonviable stimuli. J. Reticulo. Soc. 18: 14-22, 1975.